As the title asks – how can I rename files in bulk in Android?
Have a look at the below links -
Batch File Tools: Easily Rename Batch Files [Android]
Batch File Renamer Provides 5 Different Ways To Rename Files In Bulk On Android
try ES File Explorer File Manager (https://play.google.com/store/apps/details?id=com.estrongs.android.pop&hl=en) - you can do different actions in bulk for apps. I believe it also works with files.